I-line photoresist evaluations for contact hole performance with attenuated phase-shift reticles

摘要

Abstract: Evaluation of contact holes ranging from 0.35 $mu@m to 0.7 $mu@m for a number of i-line photoresists and attenuated phase-shift reticles has been completed. The study compared the effects of different photoresists patterned with a binary reticle as well as attenuated phase-shift reticles having transmission levels of 6%, 8%, and 12%. The measures of contact performance used to compare resist/reticles are focus budget, exposure latitude, and resolution. From the data collected, a large process window for sub half-micron contacts is demonstrated by using an optimum resist/reticle combination. With phase-shift, an increase in focus budget is realized with the amount of improvement dependent on the resist and transmission of the reticle. The resolution capability of all of the resists is improved by using phase-shift, although, phase-shift did not affect the linearity of the resists. Data collected points to the importance of optimizing the resist process with transmission level and applying the proper bias to maximize the focus budget. !7